Tobacco compositions, method and device for releasing essentially pure nicotine

ABSTRACT

Novel tobacco compositions which--when subjected to an elevated temperature below the combustion temperature the tobacco--liberates essentially pure nicotine.

This is a division of application Ser. No. 882,929, filed June 19, 1986now U.S. Pat. No. 4,776,353.

The present invention concerns tobacco compositions and a non-combustionmethod of liberating essentially pure nicotine from such compositions.It also includes a device for carrying out the method.

It is now widely recognized that smoking can be a major health hazard.This hazard can be cut down by reducing or eliminating smoking, butsmokers find this extremely difficult and it is generally accepted thatthis difficulty is caused by nicotine-dependence. While the presence ofnicotine in tobacco smoke is considered a risk factor, there are other,more important risk factors in the substances formed during thecombustion of tobacco such as carbon monooxide, tar products, aldehydesand hydrocyanic acid.

One way of eliminating risk factors other than nicotine is disclosed inthe U.S. Pat. No. 4,284,089. According to this patent pure nicotinevapors are obtained when air is drawn through a device containing anicotine mixture disposed within an absorbent member. The nicotinemixture may be selected from the group consisting of nicotine (d),nicotine (1), nicotine (d,1), nicotine salts and nicotine esters.

The U.S. Pat. Nos. 4,141,369 and 4,219,032 disclose devices fornon-combustion utilization of tobacco. These devices are concerned withdesigns of the devices different from that according to the presentinvention. Besides, no information is given on the amount or the purityof nicotine obtained when gas from these devices is inhaled.

OBJECTS OF THE INVENTION

It is an object of the invention to provide a novel tobacco compositionwhich--when air is drawn therethrough for inhalation purposes--liberatesessentially pure nicotine.

A second object of the invention is to provide a non-combustion methodof liberating essentially pure nicotine for inhalation purposes from thenovel tobacco composition.

A third object of the invention is to provide a non-combustion method ofliberating essentially pure nicotine from the novel tobacco compositionsaccording to which essentially the same rate and amount of nicotinerelease is obtained at inhalation as when smoking the correspondingamount of tobacco.

A fourth object is to provide a non-combustion method of liberatingessentially pure nicotine from the novel tobacco compositions, whichmethod requires only moderately elevated temperatures at whichessentially no thermal decomposition products are formed.

A fifth object of the invention is to provide a device that can be usedfor the inhalation of nicotine from the novel tobacco composition.

A sixth object of the invention is to provide a nicotine releasingproduct that can be handled in substantially the same way as the tobaccoproducts presently used, which is not clumsy or complicated and whichcomprises the device having the novel tobacco compositions includedtherein.

SUMMARY OF THE INVENTION

The invention concerns novel tobacco compositions liberating essentiallypure nicotine when air is drawn through the composition for e.g.inhalation purposes. The compositions include as major constituentstobacco, water and a basic substance. Optionally oils, detergents and/orflavoring agents may be added to the compositions.

The invention also concerns a non-combustion method of liberatingessentially pure nicotine from these tobacco compositions, comprisingthe steps of mixing a tobacco material optionally containing oils,detergents and/or flavoring agents with water and a basic substanceoptionally dissolved or dispersed in the water. The composition obtainedis heated to a temperature below the combustion temperature of thetobacco but sufficiently high to liberate nicotine in an amount and at arate similar to that obtained at smoking when air is drawn through thecomposition.

The device for the release and administration of nicotine according tothe invention comprises receiving means (10, 30) which has a space (11,31) provided with an inlet and an outlet (12, 36) and in which a matrixsuch as the novel tobacco compositions containing the nicotine isinsertable, and a mouthpiece (19, 32) communicating with the outlet (12,36) of said receiving space. The device is characterized by a heatingelement (14; 40; 46, 47; 49, 50) associated with said receiving space(11, 31), said element being adapted upon manual activation to produceheat in said space (11, 31), and means (17; 41) for restricting thetemperature in the receiving space (11, 31) to a predetermined valuebelow the combustion temperature of the matrix.

DETAILED DESCRIPTION OF THE INVENTION

The tobacco compositions according to the invention includes a mixtureconsisting essentially of tobacco, water and a basic substance. Thewater might be added to the tobacco in the form of ordinary drinkingwater. Before mixing the tobacco and water it might be preferable todissolve or disperse the basic substance in the water. The tobaccocompositions according to the invention might also contain the water inthe form of water-containing salt or in the form of heatsensitivemicrocapsuls. Examples of watercontaining salts are soda or zeolites.Other representative examples are calcium hydrates such as calciummonohydrate, dihydrate or hexahydrate, sodium pyrophosphates such as Na₄P₂ O₇ 10 H₂ O or Na₄ P₂ O₇ 6 H₂ O, or sodium ortophosphates such as Na₂HPO₄ 7 H₂ O or Na₂ HPO₄ 12 H₂ O. The "dry" water contained in thewatercontaining salts and in the microcapsuls is set free at theelevated temperature required according to the invention and a wet basictobacco composition is obtained. This composition is capable ofreleasing nicotine at inhalation in an amount and at a rate similar tothat which is obtained when smoking.

Special advantages can be obtained by using Na₂ CO₃ 10 H₂ O. This saltcontains water to such an amount that it will not be necessary to addfree water at the same time as a basic substance necessary to get therequired pH is provided. In order to obtain an effective amount ofnicotine, i.e. an amount of the same magnitude as when smoking, it isrequired that the pH of the tobacco compositions according to thepresent invention exceeds 7. Preferably the pH shall exceed 8 and mostpreferably 8.8. There seems to be no need to use a pH above 12 and withordinary tobacco there seems to be no need to use compositions having apH above 10. However, the upper limit of the pH can be decidedseparately and according to taste, desired nicotine release and otherparameters known to the man skilled in the art.

As pointed out previously a certain amount of water is necessary inorder to get a satisfactory nicotine release. It should be pointed outin this context that tobacco contains water in amounts varying between 5and 25 percent (weight/weight) of the tobacco. For the same reasons asdiscussed above as regards the pH it is obvious that the water contentof the tobacco composition according to the invention can vary within awide range. Good results as regards the nicotine release have beenobtained with tobacco compositions having a water content varyingbetween 0.25 and 7, preferably between 1 and 5, g water per g ordinarytobacco. At present the most favourable results have been obtained withabout 3 g water/g ordinary tobacco.

In addition to soda the basic material might be selected from a widevariety of substances which, of course, shall be non-toxic andpreferably tasteless or palatable. Examples of suitable basic substancesto be incorporated in the tobacco compositions according to theinvention are carbonates or hydroxides of sodium, potassium or calcium.

Various additives can be incorporated into the tobacco compositionsaccording to the invention in order to improve its characteristics.Examples of such additives are oils, e.g. silicone oils and paraffineoils, detergents, e.g. polyoxyethylene ethers such as Brij™ or Tween™and flavoring agents, e.g. menthol, anis.

The present invention also concerns a method for liberating essentiallypure nicotine from tobacco for inhalation purposes. This methodcomprises the steps of mixing a tobacco material optionally containingoil, detergent and/or flavoring agents with water and a basic substanceoptionally dissolved or dispersed in the water and heating thecomposition obtained to a temperature sufficient to liberate anefficient amount of nicotine but below the combustion temperature of thetobacco. As previously described the water may be in the form of a watercontaining salt or in the form of heatsensitive microcapsules andoptionally the water and the basic substance may be provided in the samesubstance, e.g. soda.

As described above the efficient amount of nicotine is an amountcorresponding to the amount that the smoker obtains when smoking. Thetemperature required in order to obtain this amount on the compositionused can be easily determined by simple experiments. Usually thetemperature required varies between 30° and 200° C. and preferablybetween 50° and 100° C. The most favourable results have been obtainedby using temperatures between 70° and 80° C. In order to reach thedesired temperature rapidly it might be suitable to subject the tobaccocompositions to a higher temperature initially. When the water ispresent in bound form in the tobacco composition free water will beliberated upon heating.

The following tests illustrate the release of nicotine from thecompositions according to the invention:

Small glass columns were packed with tobacco compositions according tothe invention. The tobacco compositions consisted of 1 g of tobacco thathad been soaked with 2 ml of a saturated aqueous sodium carbonatesolution. Untreated tobacco was used as reference. Air (1 liter) wasblown through each column at a rate of 50 ml/3-4 Ts with a syringe andthe released nicotine was collected in sulphuric acid solution. UVabsorption measurements indicated that essentially pure nicotine wasliberated.

The following results were obtained:

    ______________________________________                                                                   Released nicotine                                  Tobacco composition                                                                         Temperature ° C.                                                                    mg/l air                                           ______________________________________                                        According to the                                                                            35            0.05-0.10                                         invention                                                                     According to the                                                                            55           approx. 0.50                                       invention                                                                     According to the                                                                            75           approx. 2.20                                       invention                                                                     Untreated     75           approx. 0.03                                       ______________________________________                                    

The bioavailability of nicotine, i.e. the blood plasma nicotine levels,after inhalation of air from the glass columns prepared as describedabove at 65° C. and 75° C., respectively was also investigated. The testpersons had abstained from smoking or having nicotine in any other wayfor 12 h before the test.

The following plasma peak values wereobtained:______________________________________Temperature ° C. Plasmanicotine ng/ml______________________________________65 57510-15______________________________________

A device for the release and administration of nicotine from thecomposition described above should comply with two importantrequirements. First, it must be able to produce heat of a temperaturewhich is below the combustion temperature of the matrix, i.e. tobaccocomposition, and, secondly, it must be small and easy to transport andhandle. Preferably, it should have the approximate size and shape of acigarette holder or a pipe, i.e. have the appearance of an object towhich the smoker is accustomed.

In the enclosed drawings, there are shown examples of suitable devices.

FIG. 1 is a perspective view of a device designed as a "cigarette"holder, together with a "cigarette", by which is meant a composition ofthe present invention as herein defined, in the form of a more or lessconventional cigarette, with or without an external wrapper of paper,plastic or the like.

FIGS. 2, 3 and 4 are sectional views of different designs of the deviceaccording to FIG. 1.

FIG. 5 is a sectional view of a device resembling a pipebowl.

In FIG. 1, the device according to the invention is in the form ofcigarette holder 30 defining a cylindrical space 31 which is open at oneend of the holder 30 and so dimensioned that an untipped cigarette 33 isinsertable therein substantially in its entirety with suitable friction.At the opposite end, the holder 30 is designed with a mouthpiece 32. Itappears that the cigarette holderlike device does not differ to anymajor extent from a conventional cigarette holder.

The device 30 may take the form of many different embodiments to fulfilthe objects of the invention. According to FIG. 2, the peripheral wallof the opening 31 and an outer wall 34 define between them a space ofannular cross-section having a length corresponding to that of the"cigarette" 33. At its end remote from the insertion end, the opening 31merges into an opening 36 of reduced cross-section via an abutment 37restricting the depth of insertion of the "cigarette" 33. The annularchannel defined between the walls 34, 35 is slightly widened in the areabetween the abutment 37 and the mouthpiece 32 to provide room in thiswidened space 38 for an electric battery 39. This battery 39 isconnected over a switch (not shown) to a heating coil 40 surrounding thewall 35 defining the opening 31. In the lines (not shown) between thebattery 39 and the coil 40, there is connected a circuit comprising atemperature sensor 41, preferably also comprising predeterminedtemperature maximizing and minimizing means (not shown). In the use ofthe holder according to FIG. 2, a "cigarette" 33 is introduced in theopening 31 and the switch (not shown) is activated so that current issupplied to the coil 40 which then supplies heat to the "cigarette" 33in the space 31. When the predetermined maximum temperature has beenreached, this is detected by the sensor 41 which disconnects the battery39 and reconnects it again when the lower temperature minimum isreached. The temperature in the space 31 can be maintained by means ofthe illustrated device within a desired narrow temperature range. TheFigure merely illustrates the main parts of the device schematicallywhereas such components as switches, leads, etc., are not illustratedinasmuch as the device can be modified in many different ways within thescope of the invention and the details may vary from one embodiment toanother and because such means as are not illustrated are conventionalin the art.

FIG. 3 illustrates another embodiment of the invention, in which theelectric heating device has been replaced by a gas burner device. Thus,the walls 34 and 35 define between them a chamber 42 which can be filledwith gas through a conventional charging valve 45, e.g., of the typeused in cigarette-lighters. Between the walls, there is arranged afurther chamber 43 accomodating an igniting device 47 which may also beof the same type as employed conventionally in cigarette-lighters. Thetwo chambers are separated by a partition 44 in which a flow controlvalve 46 for controlling the flow of gas into the chamber 43 (and theninto material 48) is disposed. The remainder of the space between thewalls 34 and 35 up to the cigarette insertion end is filled with asuitable, incombustible material which is gas-permeable. To this end,use may be made of different ceramic materials in a suitable design orquite simply suitably packed temperature-stable, high surface areamaterials such as glass fibres, particles, or shreds, terracotta,mineral wool or the like. The space between the walls 34, 35 is sealedat the cigarette insertion end but has vent openings 53 to allow air andoxygen intake and gas combustion and exhaust. In the use of thisembodiment of the device the "cigarette" 33, as in the preceding case,is inserted in the space 31 and gas is thereafter supplied to thechamber 42 through the valve 45, if so required. The gas flows into thechamber 43 with the igniting means 47 through the valve 46 and is thereignited by manually activating the igniting means 47. The hot gases thenflow through the gas-permeable material 48 along the space 31 and enterthe ambient atmosphere through the openings 53. The temperature in thespace 31 is adjusted by means of the valve 46 which allows the passageof a predetermined amount of gas per unit of time, and optionally bysolution of the material 48 and the gas permeability factor thereof.When the gas permeable material 48 is ceramic it is possible topreselect the number and size of the interstices thereof per unit areaand thereby to determine the rate of gas flow therein and therethroughand the rate of gas permeation thereof, and thus also the maximumattainable temperature, so that a separate temperature control can beeliminated and a desired minimum temperature maintained by rate andamount of suction applied so long a gas is available in chamber 42. Withother gas-permeable materials, the temperature control is not inherently"built-in" and separate temperature control means should accordingly beprovided. When the gas-permeable material employed is non-catalytic orcatalytic and wholly or partially self-igniting, then no igniting meansis necessary whereas, when no part of the gas-permeable material 48 isself-igniting, then an ignition means 47 is required.

FIG. 4 illustrates a very simple embodiment of the device according tothe invention in which the required heat is produced by means of twoliquids 49 and 50 which are enclosed in the space between the walls 34and 35 and separated by means of a partition 51. The liquids 49, 50 areselected from the group of liquids which produce heat when mixed witheach other. In the device according to FIG. 4, the part of the devicecontaining the opening 31 is first bent back and forth, whereby thepartition 51 of brittle material is broken and the liquids 49, 50 aremixed with each other so as to generate the required heat. The"cigarette" may of course also be inserted before the wall 51 is broken.In this embodiment, the mouthpiece 32 has micro-size through openings 52to allow air to enter into the opening 36 through which the nicotinepasses to cool the same before entering the mouth.

The above-described devices are made of a suitable heat-insulatingmaterial so that the mouthpiece 32 held between the lips will not becometoo hot and uncomfortable.

FIG. 5 illustrates an embodiment of the device according to theinvention which takes the form of a pipe-bowl 10. The pipe-bowl, whichmay be made of wood or any other suitable material, defines in aconventional way a cup-shaped cavity 11 having a gas outlet 12 adjacentits bottom and an air inlet 13. The air inlet 13 may also be arranged ina cover 15 to be placed on the top face of the pipe-bowl 10. Along itssides and bottom, the cavity 11 has a heating element 14, e.g., in theform of a heating coil. This heating coil is connected to a battery 16by an electronic circuit 17 including a manually operable switch andsensor (not shown) operating in the same way as the sensor 41. Thebattery is maintained in place by means of a screw plug 18. A pipe-stem19 is connected to the bowl 10 by a threaded portion 20. The deviceaccording to FIG. 5 functions in substantially the same manner as thedevice according to FIG. 2, except for the fact that loose tobacco, andnot a "cigarette", is placed in the receiving space 11.

We claim:
 1. Tobacco compositions having a pH exceeding 7, forliberating essentially pure nicotine in effective amounts when air isdrawn therethrough and when subjected to elevated temperatures below thecombustion temperature of the tobacco, for inhalation purposes,comprising a mixture of tobacco, water, and added basic material. 2.Composition according to claim 1 characterized in that the water ispresent in the form of water-containing salt.
 3. Composition accordingto claim 2 characterized in that the water-containing salt is selectedfrom the group consisting of hydrated soda and zeolites.
 4. Compositionaccording to claim 2 characterized in that the basic material isselected from the group consisting of carbonates and hydroxides ofsodium, potassium, and calcium.
 5. Composition according to claim 2characterized in that the water is present in 0.25-7 g H₂ O/g tobacco.6. Composition according to claim 1 characterized in that thewater-containing salt is selected from the group consisting of hydratedsoda and zeolites.
 7. Composition according to claim 6 characterized inthat the basic material is selected from the group consisting ofcarbonates and hydroxides of sodium, potassium, and calcium. 8.Composition according to claim 6 characterized in that the water ispresent in 1-5 g, H₂ O/g tobacco.
 9. Composition of claim 6, wherein thepH of the composition exceeds 8.8.
 10. Composition according to claim 1characterized in that the water is present in 1-5 g H₂ O/g tobacco. 11.Composition of claim 10, wherein the pH of the composition exceeds 8.8.12. Tobacco compositions for liberating essentially pure nicotine ineffective amounts when air is drawn therethrough and when subjected toelevated temperatures below the combustion temperature of the tobacco,for inhalation purposes, comprising a mixture of tobacco, water, andadded basic material, characterized in that the water and the basicmaterial is present in the form of Na₂ CO₃.10 H₂ O.
 13. Compositionaccording to claim 12 characterized in that the water is present in0.25-7 H₂ O/g tobacco.
 14. Tobacco compositions for liberatingessentially pure nicotine in effective amounts when air is drawntherethrough and when subjected to elevated temperatures below thecombustion temperature of the tobacco, for inhalation purposes,comprising a mixture of tobacco, water, and added basic material,characterized in that the basic material is selected from the groupconsisting of carbonates and hydroxides of sodium, potassium, andcalcium.
 15. Composition according to claim 14 characterized in that thewater is present in 0.25-7 g, preferably 1-5 g H₂ O/g tobacco. 16.Tobacco compositions for liberating essentially pure nicotine ineffective amounts when air is drawn therethrough and when subjected toelevated temperatures below the combustion temperature of the tobacco,for inhalation purposes, comprising a mixture of tobacco, water, andadded basic material, characterized in that the water is present in0.25-7 g H₂ O/g tobacco.